1. Field of the Invention
This invention relates a method for producing a member having a high lubricative surface and a member having a high lubricative surface, and more particularly the same method and the same member preferably usable for metallic molds, magnetic heads, magnetic tapes, hard disks, floppy disks, pistons, products for micromachine, etc.
2. Description of the Prior Art
As a typical member having a high lubricative surface, there is a member comprising a given base material and a polytetrafluoroethylene (PTFE) material fixed on a surface of the base material. The PTFE material has a so high lubrication that the member is generally used for pistons, piston-rings, drills, bolts, nuts, dices, etc.
In the fixing of the PTFE material onto the surface of the base material, dry-processes which are typically PVD methods such as plasma polymerization, sputtering, and vacuum deposition, wet-processes which are typically coating methods such as electroless plating, dispersion plating, and electrodeposition, and complex methods of these dry-processes and wet-processes are currently proposed and practically used.
It is also suggested that in the case that the member having the high lubricative surface is worn away and the lubrication of its surface is degraded, the worn parts of the member are embedded by re-coating and thereby the member is made have lubrication.
However, the PVD methods such as the plasma polymerization, etc. require vacuum chambers which are expensive and complicate in operation. Accordingly, the production costs and the equipment costs are increased.
The wet-processes which are typically coating methods such as electroless plating, etc. require high temperature firing and long time treatment. Thus, the wet-processes restrict inevitably the sort of base material to be treated.
Even the base material usable for the wet-processes requires the optimum process for itself because the treatment such as firing for the base material is performed in a temperature range near its heat-resistant temperature. The fixing of the PTFE material onto a variety of base material requires vast equipment, resulting in the increase of the cost of the member having the high lubricative surface.
Moreover, large amounts of water and organic solvent are used in the wet-processes, which is not favorable with respect to the environment.
The PTFE material is needed to be produced from an expensive fluorine-based compound as its raw material. Thus, even if the above producing method is improved, the cost-increase of the member due to the producing of the PTFE material is not removed finally.
Moreover, even the above re-coating forms crater-like steps on the surface of the member, so that it has difficulty re-forming the surface uniformly flat and smooth. Thus, it is very difficult to give high lubrication to the worn surface of the member.